Fabric holding device



Sept. 7, 1937. J. G. LEE FABRIC HOLDING DEVICE Filed April l, 1936 INVENTOR. .UULEE A TTORNE Y Patented` Sept. 7, 1937` PATENT OFFICE FABRIC HOLDING DEVICE "John G. Lee, Farmington, Conn., assgnor to United Aircraft Corporation, East Hartford, 'Conn., a corporation of Delaware Application April 1, 1936, Serial No. 72,089 '1 Claims. (Cl. 244-132) .This invention relates to improvements in fabric holding devices and has particular reference to devices for holding the fabric covering on bodies such as the wings, tails, fuselage, or other fabric covered parts of airplanes.

An object of the invention resides in the provision of a fabric holding means of the character described whereby the fabric may be quickly' and easily secured to or removed from the body which it covers.

A further object of the invention resides in I the provision of fabric holding means of the character described so constructed as to produce a smooth external surface, free from projections extending above-'theplane of the general top or outer surface of the fabric covering.

Other; objects and advantages will be more particularly pointed out hereinafter or will become apparent as the description proceeds.

In the accompanying drawing in which like reference numerals are 4used to designate similar parts throughout, there has been illustrated and described a suitable mechanical embodiment of what is now considered to be the preferred form of the idea of the invention, It is to be understood, however, that the drawing is for the purpose of illustration only and is not to bec'onsidered as limiting the invention the scope of which is to be measured entirely by the scope of the appended claims.

In the accompanying drawing, Fig.,1 is a perspective view, partly in section, illustrating the application of, the device of the invention to securing the fabric covering upon a body such as an airplane wing, certain portions of the fuselage and fabric coveringtherefor being broken away to better illustrate the construction of the device of the invention.

Fig. 2 is a vertical sectional view through one of the airplane wing ribs showing the application of the device of the invention thereto.

Fig. 3 is a top plan view of an airplane rib showing the device of the invention applied thereto, the fabric covering being omitted for the purpose of clearness in the illustration.

Referring to. the drawing in detail, the numeral I0 indicates the upper member of a longitudinally extending spar of a hollow 'body' such as an airplane wing. This upper member I0 may be connected to a similar lower member by the spaced web members I2 and I4. Extending across or from each side of the spar are rib sections |6 and i8, each rib being made up of a plurality of such sections which together constitute a .transverse frame of airfoil contour Within the wing. A plurality of such ribs are disposed at spaced intervals along the length of the longitudinal spar and are internally braced and also braced together by suitable reinforcing means as indicated at 20 to constitute a wing frame of airfoil section. The wing frame is covered on both its upper and' lower surfaces by a suitable covering 22 to constitute the completed wing. Ihis covering, which may be a suitable fabric, may cover the entire surface of the wing or may supplement a metallic or wooden covering for certain parts of the wing.

It has formerly been the practice to secure such a fabric covering to an airplane wing or other similar body by either sewing the fabric to the wing frame members or by extending stitches entirely through the wing to simultaneously secure the coverings of the two opposite surfaces to the wing frame. When the fabric is sewed on in this manner, threads and knots are left exposed upon the exterior surface of the cover and are covered over by strips cemented to the fabric. As the knots and threads raise the strips considerably above the surface of the fabric in various places, the result has been that a smooth wing surface has by this method been impossible of attainment. Furthermore, 'many of the processes by which the fabric is sewed to the wing frame members are extremely tedious to carry out, and require an undue amount of time besides failing to produce a smooth and neat 1inished job.

The device of this invention finds its most suitable application in connection with metal frames: such as are extensively in use at present, although its application to wooden frames is not to be considered as outside of the scope of the invention.

In metal wing frames of the character indicated, the rib sections are formed up of cap strips having a generally T-shaped section comprising a hollow U-shaped stem portion 2 4 providing a` longitudinal groove, and oppostel-y extending ange portions 26 and 28. The ange portions are curved where they join the web portion to 45 provide a relatively deep groove along the tops of the cap strips. 4

In applying the device of the invention to such a rib construction, anchor members 30, preferably formed of metal, each having a substantially 50 bers have a length somewhat less than the depth of the stem portion 24 and are secured' in the groove of the rib section so that the tops of the hooks 32 are substantially on an even level with the top surfaces of the anges 26 and 28. As indicated in Fig. 1 the anchor members are mounted in the rib section so that the open sides of the hooks of alternate anchor members face in opposite directions as indicated at 38, 40, and 42.

Reinforcing strips 44 are applied to the surface of the fabric along the portions overlying the rib sections, such reinforcing strips being securely attached to the fabric by a suitable cement, paint or dope. The reinforcing strips and the fabric covering are provided with suitable slits or aper-v -tures 46 positioned so'that the upper ends of the anchor members 30 will extend through the slits when the fabric is applied to the wing frame. After the fabric has been applied to the wing frame as indicated above, and the upper ends of the anchor members 30 projected through the slits 46, a securing member such as a cord, cable, or metal wire 48 is laced into the hook portions on the upper ends of the anchor members so that it will overlie the upper surface of the covering. As stated above, the -hook portions of alternate anchormembers are faced in opposite directions, these anchor members are also so spaced along the length of each rib section, and the hooks are so located with respect 'to the thickness of the anchor members, that the wire 48 is slightly bent, as clearly indicated in Fig. 3, between adjacent anchor members. Owing to the stiffness or resiliency of the wire, or the tension placed on the cord if a cord is used, this construction tends to hold the securing member securely in the hooks of the anchor members. It will be observed that the wire, or cord, may be applied to or removed from the anchor members simply by lacing it into or unlacing it from the hook portions 32.

After the wire has been applied to the hook members so that it overlies the upper surface of the fabric covering, a fabric strip 50 is applied to the fabric covering 22 overlying the Wire 48 and the upper ends of the anchor members 30. 'I'hisstrip is securely cemented to the upper surface of the fabric and, there being no projection above the fabric surface, lies at upon the surface of the fabric and does not, to anyl appreciable extent, interrupt the smooth continuity of the surface of the covering.

The anchor members 30 may also have the additional utility of serving as riveting blocks for the ends of various brace members 20 which are connected to the rib sections, thus reducing the weight of the wing structure by rendering it unnecessary to apply additional riveting blocks for these members.

In order to place the lacing wire 48 above the upper surface of the fabric, and at the same time maintain the upper surface of the wire and the upper ends of the anchor members 30 below the general plane of the upper surface of the fabric covering, it has been found necessary to bend the fabric downwardly into the groove 34 between the rib anges 26 and 28 as indicated at 52. This construction, however, has been found to have decided advantages in that it is possible by this means to stretch or tighten the fabric while it is being applied to the Wing, and once applied, the fabric is securely held against any tendency to creep or Wrinkle along the members of the wing frame to which it is attached.

aooacvc the same, what it is desired to secure by Letters Patent is as follows:

1. In aircraft construction a body having a grooved frame and a .fabric covering for said body stretched over said frame, means 'for securing said fabric on said body comprising, anchor members secured to said frame in said grooves and in spaced position along said grooves, and a lacing member secured to said anchor members on the side of said fabric opposite said frame, said anchor members and said lacing member having all of their surfaces within the respective grooves.

2. In aircraft construction a body having a grooved frame and a fabric covering, means for holding said covering on said frame comprising, a plurality of anchor members each provided with a hook at one end thereof arranged in spaced relation along and within said frame grooves so that said hooks of alternate anchor members face in opposite directions and extend through said covering but are positioned entirely within said grooves, and a resilient lacing member secured in said oppositely facing hooks and extending across the outer surface of said covering.

3. In aircraft construction a body having a holding said covering on said frame comprising,

a plurality of anchor members each provided l with a hook at one end thereof arranged in spaced relation in and along said frame slots so that said hooks vextend through said covering but are positioned entirely Within said grooves, and a resilient lacing member secured in said hooks and extending across the outer surface of said covering, said covering being provided with slits or apertures through which said hook portions extend, and a reinforcing strip provided with correspondingslits disposed along each apertured portion of said covering and securely cemented thereto to reinforce said covering at said coverlng securing means.

4. In an airplane wing having a frame including ribs having longitudinal grooves therein, and a covering for said wing, a covering holding means comprising anchor members secured at spaced intervals-in said grooves and positioned entirely within said grooves, each anchor member being provided at its outer end with a hook portion projecting through said covering, and a resilient lacing member engaged in said hook portions along each rib and extending across the outer surface of said covering.

5. In an airplane wing having a frame including ribs formed of cap strips having hollow web portions and oppositely diverging ange portions, and a covering for said. Wing, means for securing said covering to said ribs comprising, anchor members secured at spaced intervals in said hollow web portions, each anchor member being provided at its outer end with a hook portion projecting through said covering, and a lacing member engaged in said hook portions along each rib and extending across the outer surface of said covering, said anchor members also serving as riveting blocks for various brace elements of said wing frame.

6. In an airplane wing having a frame including rib sections formed of metal cap strips having hollow web portions and oppositeiy diverging flange portions along one side of each web portion, and a covering for said frame, means for securing said covering to said rib sections comprising anchor members secured at spaced intervals in said hollow web portions, each anchor member being provided at its outer end with a hook portion projecting through said covering and a lacing member engaged in said hook portion along each rib section and extending across the outer surface of said covering, said flanges extending above said hook portions and said lacing member to bring said covering securing means within said 20 hollow web portions.

ing rib sections formed of metal cap strips each having a hollow web portion and oppositely diverging iiange portions along one side of said web portion and a covering for said wing, means for securing said covering to said wing section comprising anchor members secured at spaced intervals in the hollow web portions of said rib sections, each anchor member being provided at its outer end with a hook portion projecting through said covering, and a resilient lacing member engaged in said hook portions along each rib section and extending across the outer surface of said covering, the flanges of each rib section each having a curved portion adjacent to the web portion to provide a groove within which said covering securing means is wholly disposed and into which said covering may be depressed by said lacing member to stretch said covering on said wing frame.

JOHN G. IEE. 

